This invention relates to a composition for cleaning and wetting contact lenses which comprises a polyethyleneoxide-containing material having a hydrophile-lipophile balance (HLB) of at least about 18, a surface active agent having cleaning activity for contact lens deposits, and a wetting agent.
A care regimen for contact lenses involves various functions, such as regularly cleaning the lens with a contact lens solution containing a surface active agent as a primary cleaning agent. Rinsing of the contact lens is generally required following cleaning to remove loosened debris. Additionally, the regimen may include treatment to disinfect the lens, treatment to render the lens surface more wettable prior to insertion in the eye, or treatment to condition (e.g., lubricate or cushion) the lens surface so that the lens is more comfortable in the eye. As a further example, a contact lens wearer may need to rewet the lens during wear by administering directly in the eye a solution commonly referred to as rewetting drops.
Separate solutions may be provided for the individual savants of the care regimen. For convenience purposes, multipurpose contact lens solutions have gained popularity, i.e., solutions which can be used for several segments of the care regimen.
As an example, multipurpose contact lens solutions which can be used for cleaning, storage and conditioning of contact lenses have been suggested. U.S. Pat. No. 5,141,665 (Sherman) discloses a cleaning, conditioning, storing and wetting system for rigid gas permeable contact lenses. The system is described as including: (1) a cleaning, conditioning and storing solution; and (2) a separate wetting solution, wherein both solutions include a disinfectant or preservative. Lenses treated with the first solution are rinsed and then wet with the separate wetting solution prior to insertion in the eye.
Multipurpose contact lens solutions which effectively clean a contact lens, and can also be used to treat the lens immediately prior to insertion of the lens in the eye, represent the more difficult multipurpose solutions to develop. Conventional surface active agents having good cleaning activity for contact lens deposits, as well as various other components such as antimicrobial agents included as a preservative or disinfectant, tend to be irritating to the eye. Additionally, the surface active agents must not inhibit the wetting or conditioning function of the solution.
Multipurpose contact lens solutions for cleaning and wetting contact lenses have also been suggested which employ as the primary cleaning agent a surface active agent having minimal or no irritation. As an example, U.S. Pat. Nos. 3,882,036 and 3,954,644 (Krezanoski et al.) suggest compositions comprising a polyethyleneoxy-polypropyleneoxy block copolymer (also known as poloxamer) having minimal or no eye irritation as the primary cleaning agent.
U.S. Pat. No. 4,820,352 (Riedhammer et al.) suggests compositions for cleaning and conditioning contact lenses which are sufficiently nonirritating that a contact lens treated with the solution can be inserted directly in the eye. Preferred compositions employ as the primary cleaning agent a specific class of polyethyleneoxy-polypropyleneoxy block copolymer adducts of ethylene diamine (also known as poloxamine), which agents are both effective at cleaning and exhibit minimal or no eye irritation.
Although the specific Class of poloxamine surface active agents described in the Riedhammer patent provide good cleaning action for contact lens deposits and exhibit minimal eye irritation, other surface active agents exhibiting acceptable eye irritation levels generally have-a relatively low cleaning ability for contact lens deposits. Accordingly, this latter approach to minimize eye irritation frequently results in a sacrifice of good cleaning activity.